Hydraulic pump arrangement for internal-combustion engine

ABSTRACT

AN INTERNAL-COMBUSTION ENGINE HAS A ROD FITTED WITH A CAM FOLLOWER URGED INTO CONTACT WITH THE ENGINE CAMSHAFT. THIS ROD ACTUATES A STEPPED PISTON OF A SMALL HYDRAULIC PUMP MOUNTED DIRECTLY ON THE ENGINE BLOCK AT THE PEDESTAL ON WHICH THE FUEL PUMP IS NORMALLY SEATED. AN END OF THE PISTON EXTENDS THROUGH THE HOUSING OF THE PUMP AND IS FITTED WITH A PLASTIC CAP ENGAGING THE ROCKER ARM OF THE ENGINE FUEL PUMP MOUNTED IN TURN ON THE HYDRAULIC PUMP HOUSING. THE CAM FOLLOWER IS AN ARCUATE SHOE ENGAGING AROUND A QUARTER OF THE SURFACE OF THE CAM AND CONNECTED TO THE ROD BY A BALL-AND-SOCKET JOINT.

March 2, 1971 I H. ERDMANN I 3,567,343

HYDRAULIC PUMP ARRANGEMENT FOR INTERNAL-COMBUSTION ENGINE Filed Feb. 4. 1969 2 Sheets-Sheet 2 'FIG.2

v 8 24 I6 44 43 37 I4 I2 57 4O 48 20 INVENTOR.

' HANS ERDMANN. BY

{Karl 7201s I ATTORNEY United States Patent 3,567,343 HYDRAULIC PUMP ARRANGEMENT FOR INTERNAL-COMBUSTION ENGINE Hans Erdmann, Neu Isenburg, Germany, assignor to Alfred Teves G.m.b.H., Frankfurt am Main, Germany Filed Feb. 4, 1969, Ser. No. 796,406 'Claims priority, application Germany, Feb. 7, 1968, P 16 01 422.5 Int. Cl. F04b 23/04 US. Cl. 417-364 Claims ABSTRACT OF THE DISCLOSURE An internal-combustion engine has a rod fitted with a cam follower urged into contact with the engine camshaft. This rod actuates a stepped piston of a small bydraulic pump mounted directly on the engine block at the pedestal on which the fuel pump is normally seated. An end of the piston extends through the housing of the pump and is fitted with a plastic cap engaging the rocker arm of the engine fuel pump mounted in turn on the hydraulicpump housing. The cam follower is an arcuate shoe engaging around a quarter of the surface of the cam and connected to the rod by a ball-and-socket joint.

My present invention relates to a hydraulic-pump arrangement for an internal-combustion engine and, more particular, for an engin having a rocker-arm actuated fuel pump and some auxiliary liquid-circulation system such as power brakes, a load-leveler suspension, the refrigeration unit of the air conditioner, hydraulic winch or lifts, power steering.

It is the customary practice to mount the hydraulic pump for power brakes or power steering, a load leveler, or a hydraulic clutch or any other liquid-operated load on its own flange on the engine. This pump is also customarily provided with its own pulley which is connected to another engine-driven pulley through a V-belt. In this manner the pump takes up space which is often excessive when considered in the light of the tasks it performs; furthermore its drive adds additional mechanism to the system which is susceptible to wear and increases the repair requirements of the vehicle.

It is, therefore, the principal object of my invention to provide a hydraulic-pump arrangement for an internalcombustion engine which overcomes these disadvantages.

A further object is to provide a pump arrangement which can be accommodated to existing engine constructions with a minimum of difficulty and trouble.

Yet a further object is to provide an improved pump arrangement which takes up a minimal amount of space and adds a minimum of new mechanism to an internal combustion engine.

I attain these objects, in accordance with a main feature of my invention, by providing a hydraulic pump means whose piston forms part of a rigid linkage that drives the fuel pump of an internal-combustion engine of the reciprocating-piston type wherein the camshaft operates the intake and exhaust valves and normally drives the fuel pump, the camshaft being coupled with the crankshaft by timing chains, gears or the like.

More particularly, the piston of my hydraulic pump, which is mounted directly on the engine block and forms a pedestal for the conventional fuel pump, is a stepped ice piston whose narrow or small diameter end extends through a seal and the wall of the hydraulic pump and engages the rocker arm of the fuel pump while its large diameter end also passes through a seal and a wall of the hydraulic pump and is coupled to a cam follower in the form of an arcuate sho e riding on the circular periphery of a cam of the engine camshaft.

The hydraulic-pump housing defines a cylinder with two lateral (inlet and outlet) openings. Each opening is equipped with a check valve such that fluid may only flow into the pumping chamber through one and out through the other. These openings, constituting the inlet and the outlet of the hydraulic pump, are advantageously of like dimensions (diameters) to make mounting easy and to allow the fittings (e.g., the check valves) to be interchangeable.

According to a further feature of my invention, the cam follower engages a good part of the cam surface via a shoe that is linked to the piston by a ball-and-socket joint.

These and other features, advantages and objects of my invention will be more fully described in the following, with reference to the accompanying drawing, in which:

FIG. 1 is a vertical cross-sectional view through an arrangement embodying my invention;

FIG. 2 is a section through the pump means of FIG. 1, drawn to in enlarged scale; and

FIG. 3 is a section according to line IIIIII of FIG. 1.

As shown in FIG. 1 an internal-combustion engine 52 of an automotive vehicle, has a block 1 and a conventional camshaft 2 carrying a cam or eccentric 3. A shoe 6 seats on this cam 3 over one-fourth of its circumference (at least for best force transmission. The upper part of this shoe 6 is provided with a ball 53 received to more than a hemisphere in a socket 54 of a slider 5 so that it cannot fall out. This slider 5 rides in a bore 4 in part of the engine housing or block 1. A rod 7 is seated in a bore 55 of the slider 5 and seats in turn in a bore 56 in the bottom of a stepped piston 8.

The top or narrow diameter end of this piston 8 is fitted with a low-friction, wear-resistant synthetic-resin cap 24 (e.g., of polytetrafluoroethylene) that engages one end of a rocker arm 25 pivoted at 36 and biased downwardly by a spring 35. The other end of the arm 25 engages the end of a rod 29 which actuates the diaphragm of a nonpositive fuel pump 23 whose spring 29a biases the diaphragm upwardly. This fuel pump has an inlet 27 with a check valve 28 and an outlet 26 which leads to the engine 52. Fuel can enter at 27 into a lower chamber 33, pass through a check valve 31 into a chamber 32, and leave via the outlet conduit 26. Up-and-down motion of the rod 29 transfers fuel from the chamber 33 to the chamber 32 in a manner well known in the art. The rocker arm can be removed and lubricated through a removable plate 34 in the side of the pump 23.

FIG. 2 shows my hydraulic pump in greater detail. Here the hydraulic pump 16 has a piston 8 whose shoulder 41 defines an upper narrow diameter portion and a lower large diameter portion. The upper portion is sealed. by a retaining washer 37 with holes 40 holding an O-ring '14 on a seal 12. The lower portion is sealed by a similar washer 38 with holes 39 on an O-ring 13 on a seal 11. The lower ring is held in place by a threaded plug 15 which permits access to the interior or a cylinder 9 while a spring 10 braced on a stop ring 58 seated on the shoulder 41 holds the washer 37 in place while simultaneously holding the piston 8 in its illustrated starting position.

Hydraulic fluid, for instance for a power brake, enters through a union-coupling 18 screwed into a bore 48 forming an inlet for the cylinder 58 and can leave through an outlet bore 47 and a ring coupling 17. The coupling 18 has a washer seal 50 and the coupling 17 an identical seal 49.

The inlet bore 48 is provided with a check valve 20 and the outlet bore 47 with a check valve 21 both of identical design. The valve 21 consists of a valve plate 42, a spider 44, a spring 43 and a pin 44 that are pressfitted together and form a captive-spring valve. The bores 47 and 48 are of identical diameter and the check valves 20 and 21 also of identical dimensions so that the connections 17 and 18 can be reversed, with similar reversal of the check valves 20 and 21 with no difficulty.

The piston 8, due to its different diameters D and d pressurizes the cylinder 9 on upward movement thereby forcing fluid out through the check valve 21, and depressurized it on descending thereby sucking fluid in through the valve 20.

The housing 57 of the hydraulic pump 16 is insulated from the cylinder head 1 by a gasket 22 that prevents dangerous heat from getting to the hydraulic fluid and fuel.

To add this hydraulic pump 16 to an existing motor one need merely remove the fuel pump 23 and replace the linkage with the rod 7, slide and shoe 6 and screw the fuel pump 23 back on with the hydraulic pump 16 sandwiched between it and the motor block 1 using cm. mounting screws 50.

The linkage is changed since the original cam follower is only meant to transmit around 6 Kp to the fuel pump. With the device according to my invention-having a broad engagement between the shoe 6 and the cam 3 to Kp can easily be transmitted. In my invention the hydraulic pump takes up only a few square centimeters of space in a motor, rather than the relatively large space usually occupied by such devices. The hydraulic pump acts as a spacer or pedestal for the fuel pump.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

I claim:

1. A hydraulic-pump arrangement comprising:

an internal-combustion engine having an engine block and a rotatable camshaft;

drive means for transforming rotation of said shaft into reciprocating motion;

pump means for generating hydraulic-fluid pressure and comprising a disk-shaped body provided with a cylinder and a piston axially and reciprocatingly displaceable therein, said piston being actuatable by said drive means; and

a fuel pump for said engine operatively connected to said piston for actuation thereby, said drive means including at least one rigid elongated member linearly reciprocable by said camshaft for actuating said piston and said fuel pump, said pump means and said fuel pump being mounted one above the other on said engine block, said disk-shaped body being directly mounted on said block and forming a. flange for securing said fuel pump on said engine block.

2. The arrangement defined in claim 1 wherein said engine is an internal-combustion engine and has an engine block, said shaft is the camshaft of said engine, said drive means including at least one rigid elongated member linearly reciprocable by said camshaft for actuating said piston and said fuel pump, said pump means and said 4 fuel pump being mounted one above the other on said engine block.

3. The arrangement defined in claim 8 wherein said cylinder further is formed with an inlet and an outlet, said pump means further comprising a respective check valve at said inlet and at said outlet, said piston being a stepped piston.

4. The arrangement defined in claim 3 wherein said stepped piston forms part of said rigid member and is provided with a shoulder defining a relatively small diameter portion and a relatively large diameter portion along said piston, said fuel pump being connected to said small diameter portion and said drive means being connected to said large diameter portion.

5. The arrangement defined in claim 4 wherein the relatively small diameter portion of said piston is provided with a cap of synthetic-resin material for actuating said fuel pump.

6. The arrangement defined in claim 1 wherein said fuel pump is mounted directly on said pump means.

7. The arrangement defined in claim 6 wherein said drive means includes a rotating eccentric cam mounted on said camshaft, and a cam follower engaging said cam, said member being operatively connected to said follower.

8. A hydraulic-pump arrangement comprising:

an internal-combustion engine having an engine block and a rotatable camshaft;

drive means for transforming rotation of said shaft into reciprocating motion;

pump means for generating hydraulic-fluid pressure and comprising a cylinder and a piston axially and reciprocatingly displaceable therein, said piston being actuatable by said drive means; and

a fuel pump for said engine operatively connected to said piston for actuation thereby, said drive means including at least one rigid elongated member linearly reciprocable by said camshaft for actuating said piston and said fuel pump, said pump means and said fuel pump being mounted one above the other on said engine block, said fuel pump being mounted on said pump means, said drive means including a rotating eccentric cam mounted on said camshaft, and a cam follower engaging said cam, said member being operatively connected to said follower, said cam having a circular periphery, said cam follower is an arcuate shoe engaging said periphery over an arc of at least said member includes a rigid rod connected to said piston and said drive means further includes a ball joint connecting said shoe to said rod.

9. The arrangement defined in claim 3 wherein said inlet and said outlet are of like dimensions, said pump means further comprising connecting means connectable to said inlet and outlet and each receiving a respective one of said check valves.

10. A hydraulic-pump arrangement comprising:

an internal-combustion engine having an engine block and a rotatable camshaft;

drive means for transforming rotation of said shaft into reciprocating motion;

pump means for generating hydraulic-fluid pressure and comprising a cylinder and a piston axially and reciprocatingly displaceable therein, said piston being actuatable by said drive means; and

a fuel pump for said engine operatively connected to said piston for actuating thereby, said drive means including at least one rigid elongated member linearly reciprocable by said camshaft for actuating said piston and said fuel pump, said pump means and said fuel pump being mounted one above the other on said engine block, said drive means further comprising a circular cam eccentrically mounted on said camshaft and a cam follower engaging said cam over an arc of at least 90 on said cam, said cam follower being formed with a ball head, said mem- 6 her including a sleeve, said sleeve being formed with comprising a rocker arm engaged by said cap, said a socket on one end receiving more than a hemiarrangement further comprising a thermally insulatsphere of said ball head, a longitudinal bore opening gasket between said pump means and said block. ing at its other end, a rod received in said sleeve and seated in said piston, said piston being a stepped 5 References Cit d piston having a shoulder defining a relatively large UNITED STATES PATENTS diameter portion and a relatively small diameter portion, said relatively large diameter portion being 1,883,459 10/1932 Avigdor 103-9X engaged by said rod, said pump means further com- 2,028,208 1/1936 Haney 103167X prising spring means biasing said piston toward a 10 2,278, 45 3/1942 Colell 103167X starting position with said large diameter portion ,755,739 7/1956 Euwe 103-9 substantially out of said cylinder, said cylinder hav- 3,051,087 3/ 1962 Scholin 10354X ing an inlet provided with a check valve permitting 3,068,794 12/1962 M ri et 1- 1 9 fluid flow into said cylinder and an outlet provided 3,260,213 7/1966 Eickmann IDS-54 with a check valve permitting fluid flow therefrom, 15 3,363,574 1/ 1968 Aldingef )UX said relatively small diameter portion having an end provided with a synthetic-resin cap, said fuel pump ROBERT M. WALKER, Primary Examiner 

